Module: Feat::Operators

Defined in:
lib/feat/operators.rb

Overview

Per-operator predicates. Defensive: type-mismatch / parse-failure returns false rather than raising — matches the JS engine’s posture against malformed contexts at the edge.

segment_match / segment_not_match are dispatched by the rule evaluator (they recurse into the datafile’s segments map), not here.

Constant Summary collapse

REDOS_SHAPES =

ReDoS guard for matches_regex. Caps pattern length and rejects the most common catastrophic-backtracking shapes. False positives just turn the rule into a non-match, which is the safe default.

/\([^)]*[+*][^)]*\)\s*[+*]|\([^)]*\|[^)]*\)\s*[+*]/
SEMVER_RE = 
/\A(\d+)\.(\d+)\.(\d+)(?:-([0-9A-Za-z.-]+))?(?:\+[0-9A-Za-z.-]+)?\z/

Class Method Summary collapse

Class Method Details

.any_eq?(lhs, values) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/feat/operators.rb', line 81

def any_eq?(lhs, values)
  values.any? { |v| deep_eq(lhs, v) }
end

.any_string_value?(values) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/feat/operators.rb', line 91

def any_string_value?(values)
  values.any? { |v| v.is_a?(String) && yield(v) }
end

.compare_semver(a, b) ⇒ Object 



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# File 'lib/feat/operators.rb', line 157

def compare_semver(a, b)
  3.times { |i| return a[i] - b[i] if a[i] != b[i] }
  ap, bp = a[3], b[3]
  return 0 if ap == bp
  return 1 if ap.nil?
  return -1 if bp.nil?

  ap <=> bp
end

.date_cmp(lhs, values) ⇒ Object 



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# File 'lib/feat/operators.rb', line 115

def date_cmp(lhs, values)
  a = to_time(lhs)
  return false if a.nil?

  values.any? do |v|
    b = to_time(v)
    b && yield(a, b)
  end
end

.deep_eq(a, b) ⇒ Object

JS-engine-compatible equality with string/number coercion.



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# File 'lib/feat/operators.rb', line 62

def deep_eq(a, b)
  return true if a == b

  if a.is_a?(Numeric) && b.is_a?(String)
    return a.to_s == b || float_eq(a, b)
  end
  if a.is_a?(String) && b.is_a?(Numeric)
    return a == b.to_s || float_eq(b, a)
  end

  false
end

.empty?(lhs) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/feat/operators.rb', line 57

def empty?(lhs)
  lhs.nil? || lhs == ""
end

.float_eq(num, str) ⇒ Object 



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# File 'lib/feat/operators.rb', line 75

def float_eq(num, str)
  Float(str) == num.to_f
rescue ArgumentError, TypeError
  false
end

.match(operator, lhs, values) ⇒ Object 



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# File 'lib/feat/operators.rb', line 14

def match(operator, lhs, values)
  case operator
  when "is_one_of"        then any_eq?(lhs, values)
  when "is_not_one_of"    then !any_eq?(lhs, values)
  when "is_empty"         then empty?(lhs)
  when "is_not_empty"     then !empty?(lhs)
  when "contains"         then string_any?(lhs, values) { |s, v| s.include?(v) }
  when "does_not_contain"
    return true unless lhs.is_a?(String)

    !string_any?(lhs, values) { |s, v| s.include?(v) }
  when "starts_with"      then string_any?(lhs, values) { |s, v| s.start_with?(v) }
  when "ends_with"        then string_any?(lhs, values) { |s, v| s.end_with?(v) }
  when "matches_regex"
    return false unless lhs.is_a?(String)

    any_string_value?(values) { |v|
      next false unless safe_regex?(v)

      begin
        !!(lhs =~ Regexp.new(v))
      rescue RegexpError
        false
      end
    }
  when "gt"               then numeric_cmp(lhs, values) { |a, b| a > b }
  when "gte"              then numeric_cmp(lhs, values) { |a, b| a >= b }
  when "lt"               then numeric_cmp(lhs, values) { |a, b| a < b }
  when "lte"              then numeric_cmp(lhs, values) { |a, b| a <= b }
  when "before"           then date_cmp(lhs, values) { |a, b| a < b }
  when "after"            then date_cmp(lhs, values) { |a, b| a > b }
  when "semver_eq"        then semver_cmp(lhs, values) { |c| c.zero? }
  when "semver_gt"        then semver_cmp(lhs, values) { |c| c.positive? }
  when "semver_gte"       then semver_cmp(lhs, values) { |c| c >= 0 }
  when "semver_lt"        then semver_cmp(lhs, values) { |c| c.negative? }
  when "semver_lte"       then semver_cmp(lhs, values) { |c| c <= 0 }
  when "segment_match", "segment_not_match"
    false
  else
    false
  end
end

.numeric_cmp(lhs, values) ⇒ Object 



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# File 'lib/feat/operators.rb', line 95

def numeric_cmp(lhs, values)
  a = to_number(lhs)
  return false if a.nil?

  values.any? do |v|
    b = to_number(v)
    b && yield(a, b)
  end
end

.parse_semver(x) ⇒ Object 



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# File 'lib/feat/operators.rb', line 148

def parse_semver(x)
  return nil unless x.is_a?(String)

  m = x.strip.match(SEMVER_RE)
  return nil if m.nil?

  [m[1].to_i, m[2].to_i, m[3].to_i, m[4]]
end

.safe_regex?(pattern) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/feat/operators.rb', line 139

def safe_regex?(pattern)
  return false if pattern.length > 512
  return false if REDOS_SHAPES.match?(pattern)

  true
end

.semver_cmp(lhs, values) ⇒ Object 



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# File 'lib/feat/operators.rb', line 167

def semver_cmp(lhs, values)
  a = parse_semver(lhs)
  return false if a.nil?

  values.any? do |v|
    b = parse_semver(v)
    b && yield(compare_semver(a, b))
  end
end

.string_any?(lhs, values) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/feat/operators.rb', line 85

def string_any?(lhs, values)
  return false unless lhs.is_a?(String)

  values.any? { |v| v.is_a?(String) && yield(lhs, v) }
end

.to_number(x) ⇒ Object 



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# File 'lib/feat/operators.rb', line 105

def to_number(x)
  case x
  when Numeric then x.to_f
  when String
    Float(x)
  end
rescue ArgumentError, TypeError
  nil
end

.to_time(x) ⇒ Object 



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# File 'lib/feat/operators.rb', line 125

def to_time(x)
  case x
  when String then Time.iso8601(x)
  when Numeric then Time.at(x.to_f / 1000.0)
  end
rescue ArgumentError
  nil
end